The Berlin Wall provides a unique natural experiment for identifying the key sources of urban development. This research, for which its authors have recently been awarded the prestigious Frisch Medal, shows how property prices and economic activity in the east side of West Berlin, close to the historic central business district in East Berlin, began to fall when the city was divided; then, during the 1990s, after reunification, the same area began to redevelop. Theory and empirical evidence confirm the positive relationship between urban density and productivity in a virtuous circle of ‘cumulative causation’. The analysis has practical applications for urban planners making decisions on housing and transport infrastructure.

Trade relations between the United States and China have grown increasingly tense, spurred by concerns that growing imports from China have led to plant closures and job loss in the United States. We find a link between the sharp decline in U.S. manufacturing employment after 2000 and the granting of Permanent Normal Trade Relations (PNTR) to China, which eliminated uncertainty about China‘s continued access to the U.S. market. Our research into the reactions of U.S. and Chinese firms to PNTR highlights the sensitivity of firm behavior to policy uncertainty.

Women are often paid less than men, they are often underrepresented in leading positions, and their careers develop at a slower pace than those of men. Here, we ask to what extent these differences can be explained by childbearing. To evaluate the career cost associated with having children, we consider women’s decisions regarding labor supply, occupation, fertility and savings. We evaluate the life-cycle career cost of children to be equivalent to 35 percent of a woman’s total earnings. We further show that part of this cost arises well before children are born through selection into careers characterized by lower wages but also lower skill depreciation.

In many, many cases, people have a preference for working and doing business with those who share the same religious beliefs, come from the same geographic region, or have something else in common. If this preference arises from discrimination against other groups – if there is economically inefficient favoritism – the economy will not reach its full potential. But could there also be efficiency gains from transacting with people who are culturally proximate? If so, is it possible for the gains to be large enough to more than offset the losses from discrimination? Surprisingly, the answer to both questions is yes. However, that does not mean the barriers between groups should be reinforced. Policies that break down informational barriers between groups could produce further gains.

A central question in the US debate over privatized Medicare is whether increased government contributions to private plans generate lower premiums for consumers or higher profits for producers. This research finds that insurance companies pass through 45% of higher payments in lower premiums and an additional 9% in more generous benefits for those who enroll in Medicare Advantage. Since the findings also suggest that the less than full pass-through is a result of insurer market power, efforts to make markets more competitive may be key to increasing the pass-through to consumers.

The impact of industrial policy on China’s economic growth has been difficult to assess, in part due to the lack of direct evidence on government support measures, which remain secret. This research uncovers hidden subsidies provided to the Chinese shipbuilding industry, which has more than doubled its global market share in recent years. The subsidies decreased shipyard costs in China by 13-20% between 2006 and 2012, policy interventions that have led to substantial misallocation of global production with no significant gains for consumers. Japan, in particular, has lost market share.

The number of people living in poverty in countries around the world is commonly measured using the World Bank’s poverty line – the ‘$1 per day’ that many people have heard of, though it has risen over time and now stands at $1.90 per day. However this measure assumes that the needs of the poor are the same in every country, an assumption at odds with the evidence and common sense. This paper develops a Basic Needs Poverty Line that overcomes this problem giving us new and in some cases surprising insight into the severity of the poverty problem in both rich and poor countries around the world.

While much attention has been paid to the education premium on the labor market, little study has been devoted to the marriage market. Looking back at four decades of US marriages, this research finds that more highly educated people are more likely to marry and that their spouses tend to be of similar academic achievement. Additionally, more educated couples invest greater time in developing their children’s potential. Meanwhile, children from less educated households enjoy fewer resources and are less likely to marry highly educated spouses, the upshot of which could be less social mobility and wider economic inequality.

Regulated utilities are tasked with investing in the electricity distribution system in a way that delivers a reliable power service. This research explains how the regulatory process in the United States leads to under-investment in such infrastructure and too many power outages. The findings show how the politics of the regulatory environment can sometimes help and sometimes harm the problem of under-investment.

This paper studies the aftermath of the MillerCoors joint venture, which merged the operations of SAB Miller and Molson Coors in the United States. The prices of MillerCoors and its biggest rival, Anheuser-Busch Inbev, increased after the joint venture was consummated. These changes are consistent with post-merger coordination between MillerCoors and Anheuser-Busch Inbev.

Why are there so few women in highly paid careers as chief executives and, more generally, in finance, business, science, technology, engineering and mathematics? Analysing Danish data on young people whose educational and professional lives have been tracked over two decades since they started high school, this research suggests that part of the reason lies in restrictive bundling of courses, which deters talented young women from acquiring advanced mathematical skills. Changing the learning environment and designing the curriculum to identify and foster young women with high mathematical abilities would attract more of them and help to reduce the gender pay gap.